The specific aims of the proposed research are to determine: (1) the effects of drugs, growth factors and intraocular surgical procedures and devices on corneal regeneration; (2) the effect of corneal edema and diabetes on epithelial healing and susceptibility to infection; (3) the effects of injury, regeneration, preservation and culture on intracellular ion concentrations in corneal cells; (4) the role of infection and inflammation in the development of keratomalacia in vitamin A deficient animals and (5) the efficacy of various retinoids (vitamina A analogues) in reversing epithelial keratinization in serum-free corneal organ culture and in treating experimental xerophthalmia in vitamin A deficient animals. The overall objectives of the research are to provide information which will (1) aid in the prevention of corneal complications by providing a more rational approach to the use of drugs preservatives, surgical procedures and devices in the eye during intraocular surgery; (2) lead to a better understanding of epithelial healing and secondary infection problems in patients with chronic corneal edema and diabetes; (3) lead to a better understanding of cellular control mechanisms in injured, perserved and proliferating corneal cells; (4) provide a better understanding of the pathogenesis of keratomalacia in vitamin A deficiency; and (5) lead to better modes of therapy for the prevention and/or cure of xerophthalmia, keratomalacia and epithelial healing problems. The methods to be used include biomicroscopy; specular, light, transmission, scanning and transmission electron microscopy; energy dispersive x-ray analysis; autoradiography, tissue and organ culture.